Bold but brooding retelling of the Arthurian legend in which the once and future king (Clive Owen) is a Roman commanding an elite cavalry unit during the closing days of the Empire, who, along with Guinevere (Keira Knightley), reimagined here as a feisty female warrior, must fend off the savage barbarian hordes bent on conquering Britain. Full of dreary Dark-Age atmospherics and clashing chain-mailed armies, the film, directed by Antoine Fuqua, strips the legend of its storybook romance in favor of gritty, historical realism, but in the process paganizes what has traditionally been a quintessentially Christian myth. Intense battlefield violence, a shadowy sexual encounter, negative representation of church figures and some crude humor. The USCCB Office for Film & Broadcasting classification is L -- limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association of America rating is PG-13 -- parents are strongly cautioned. Some material may be inappropriate for children under 13.